Nonambipolarity of fluctuation-driven fluxes and its effect on the radial electric field - art. no. 195003

The nonambipolarity of the fluctuation-driven particle transport is demonst rated experimentally. Convective radial transport of electrons by fluctuati ons is found to be significantly stronger than that of ions, leading to a m ean fluctuation-driven radial current balanced in steady state by other bip olar particle losses. Fluctuation suppression leads to a sudden disappearan ce of this current and results in significant modification to the radial el ectric field. The observed change in the electric field is in good agreemen t with the measured fluctuation-driven flux.